Automated assembly of the component parts used within molded case circuit breakers suggests an attractive reduction in circuit breaker assembly time and a corresponding increase in the circuit breaker calibration yield. An automated circuit breaker design for residential type circuit breakers is found within U.S. Pat. No. 4,513,268, which patent is incorporated herein for reference purposes. The relatively small number of parts used within the residential circuit breaker design facilitates assembling the components in a completely automated process.
With larger ampere-rated circuit breakers, such as used within lighting panelboards commonly employed within industrial buildings, both the number of components and the component size are larger than those required for residential application. One example of a lighting panelboard circuit breaker design that is partly assembled on automatic equipment is found within U.S. Pat. No. 4,622,530, entitled "Circuit Breaker Assembly For High Speed Manufacture", which patent is incorporated herein for purposes of reference. The circuit breaker is assembled, in part, on automated equipment by first arranging the circuit breaker components within a plurality of sub-assemblies by hand in an off-line assembly process.
Molded case, industrial-rated circuit breakers containing either thermal-magnetic or electronic trip units are not currently designed for high speed assembly processes. Due to the large number of components required within the operating mechanism, trip unit and latch assembly, a skilled operator is needed to assemble the component parts and to individually calibrate the complete breaker before shipment. Since component parts of differing size are required for the various ampere-rated circuit breaker designs, a large inventory of component parts for each ampere rating must be maintained. The size of the components is scaled in proportion to the ampacity requirements for each of the circuit breaker ampere ratings.
One purpose of the instant invention is to describe a circuit breaker operating mechanism used within the large industrial-rated breakers, which operating mechanism is mainly manually assembled in an automated manufacturing process.